Climate Adaptation Design Principles for Urban Development

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Purpose of this Document The purpose of this document is to outline design principles that can be used to help develop policy and regulations for property in Honolulu’s transit-oriented development (TOD) and other urban areas that may be vulnerable to sea level rise (SLR) and other climate change-related hazards. The guidance in this document identifies recommended tools and best practices to consider in designing building sites and structures to be resilient to SLR, flooding, extreme heat, and groundwater inundation. A companion document, Climate Adaptation: Background Research, summarizes international best practices and local initiatives related to climate adaptation in the built environment, including recommendations for next steps. The companion document is available at www.honolulu.gov/tod. Why Design for Climate Resilience? Climate change will affect all aspects of addition to mitigating emissions, the City Scan here for life in Hawai‘i, from natural ecosystems to recognizes that adaptation will be needed the companion human health and the built environment. It is as SLR and other climate-related impacts Background imperative to plan for it now. Many U.S. cities intensify. This will require measures to Research are doing so by adopting new regulations protect or enhance existing development, document and design guidelines to make the built as well as determining when retreat or environment more resilient to SLR flooding, relocation is called for. heat, gradual inundation, and other hazards. Policies are being established in new and In developing this guidance, examples were existing documents, including sustainable consulted from New York, Boston, San community/development plan updates. Francisco, Miami, New Orleans, and other Changes to regulations for both public similar cities around the world to identify and private development are also being best practices applicable to Honolulu. considered, some of which are highlighted on the next page. In anticipation of more www.honolulu.gov/rep/site/ How is the City Addressing dpptod/climate_docs/Climate_ requirements to enhance resilience in Adaptation_Background.pdf Resilience to Climate Change? the planning, design, and construction of The City and County of Honolulu (the City) has building and infrastructure projects, the Scan here committed to plan for and adapt to the effects City will increasingly look for developers to for the O‘ahu of climate change through the establishment consider climate change and incorporate Resilience and actions of its Office of Climate Change, best practices for mitigation. Strategy Sustainability, and Resiliency (CCSR) and Developers and design professionals may the Honolulu Climate Change Commission. choose to utilize these principles as well Mayor’s Directive 18-2 (2018) requires all when developing new project applications, City agencies, departments, and consultants or when considering adaptation options to City projects to consider climate change for existing projects. However, the current and SLR in all City plans, programs, and regulatory framework may limit the ability capital improvement projects, and to apply to implement certain strategies. At the same planning benchmarks assuming 3.2 to 6 feet time, the discretionary review processes of SLR by the end of this century. may provide some flexibility, such as through www.resilientoahu.org/ In 2019, the CCSR prepared the O‘ahu TOD permits. resilience-strategy Resilience Strategy for the City with 44 Learning from any interim/pilot projects actions to guide implementation. The CCSR will further inform development of the is now preparing a Climate Action Plan to City’s climate change adaption policies and mitigate greenhouse gas emissions. In regulations, which are expected to take years to fully implement.

1 Climate Adaptation Design Principles for Urban Development What Regulatory Changes are Anticipated? Key City regulations and policies that have been recently updated or are in the process of being updated to incorporate resilient design principles are summarized below. Ordinances & Codes Climate Resilience Design Guidelines: Building Code: Action 14 of the City’s Resilience Strategy calls for the The City has adopted the 2012 International Building City to establish Future Conditions Climate Resilience Code (IBC) and International Residential Code (IRC), as Design Guidelines that incorporate forward-looking incorporated into the Revised Ordinances of Honolulu climate change data and provide specifications to inform (ROH) Chapter 16. the design of City and private facilities and infrastructure (essentially expanding on this document). The 2012 IBC requires new construction to be designed with one foot freeboard* above current Base Flood Stormwater Utility: Elevation (BFE) in hazardous flood zones. The 2012 In accordance with Action 31 of the City’s Resilience IRC limits impervious surfaces of some residential Strategy, the City is exploring the formation of a developments to 75 percent of the total lot area. The stormwater utility. This would establish fees for 2018 IBC is anticipated to be adopted in 2021. It contains impervious surfaces and further incentivize the use of additional provisions for resilience. green infrastructure, LID, and water conservation in new development and redevelopment. For more information, Flood Hazard Areas: see www.stormwaterutilityoahu.org. Following adoption of the 2012 IBC, amendments to ROH Chapter 21A are forthcoming to reflect changes in Urban Tree Canopy: the requirements for designing buildings in flood hazard In accordance with Action 33 of the City’s Resilience areas. Strategy, the City is establishing policies and practices that improve the management of trees to mitigate increasing Plumbing Code: temperatures resulting from climate change. Mayor’s The City is proposing updates to the Plumbing Code Directive 20-14 (2020) requires City departments and (ROH Chapter 19) that would allow more applications agencies to consider climate change mitigation and for on-site water reuse for residential and commercial environmental benefits of a healthy urban tree canopy properties. when making decisions that affect city trees. This policy Rules Related to Water Quality: requires the protection of trees that pose no threat to The 2018 update incorporates requirements for low safety and do not undermine an essential government impact development (LID), green infrastructure, and function, as well as planting more trees to expand urban source control best management practices (BMPs). Other canopy. updates are underway or expected to be formalized into A TOD Street Tree Plan is under development. This plan updated City codes and regulations within the next one will provide guidance for street tree type selection to to five years. maximize canopy and streetscape coherency in the TOD Special Management Area and Shoreline Setbacks: neighborhoods. A working group is preparing updates to regulations of How to make buildings and sites more resilient? the Shoreline Setbacks (ROH Chapter 23) and Special Management Area (ROH Chapter 25) to incorporate International, national, and local best practices and State-identified Sea Level Rise Exposure Areas (SLR-XA) tools that can be used to make buildings and sites more and improved mapping. resilient are highlighted on the following pages. These practices and tools are presented in four categories: Plans, Programs, & Policies Climate Adaptation Strategy: A: Understanding Applicable Hazards Action 28 of the City’s Resilience Strategy calls for the B: Managing Stormwater preparation of an O‘ahu Climate Adaptation Strategy, C: Design for Flooding and Sea Level Rise which the City has initiated. The Strategy is expected to D: Mitigating Extreme Heat include policy guidance and a recommended framework In addition, resilient design best practices are illustrated for approaching adaptation islandwide. However, it for three urban building typologies: will not recommend specific adaptation strategies at a regional or neighborhood scale. Regional or 1: Tower & Podium neighborhood scale adaptation strategies will need to 2: Mid-Rise continue to be developed through community, special 3: Low-Rise Walk-Up district, and functional plans. For more information, see www.climatereadyoahu.org.

* Italicized terms are defined at the end of this document

Climate Adaptation Design Principles for Urban Development 2 A: Understanding

Applicable Hazards How to Use the Climate Ready O‘ahu Web Explorer: Explore the map by zooming A first step in resilient design is to identify and utilize around or searching by address current information on climate science and hazards or Tax Map Key (TMK), and to determine what hazards may affect the property or investigate which areas of the building site. This information can be used to inform island are projected to be at risk siting and design of structures to support reduced risk, of flooding (due to SLR and/or rainfall) and extreme heat (due enhanced safety, and long-term protection of natural to rising temperatures and the systems, people, and structures. Land use, community urban heat island effect). planning, and zoning practices are critical implementation Different layers can beturned tools for long-term hazards and financial risk mitigation on or off and expanded in the for the City, its residents, and businesses. Layers tab (stacked papers The Climate Ready O‘ahu Web Explorer icon). Some layers require (bit.ly/climatereadyoahumap) is an online mapping tool zooming in to view and take longer to load. Additional map that features data from the City, State, and Federal resources, information, and governments. The data represents best available metadata are available on the science for a variety of climate change stressors and Details tab (information “i” icon other regulatory layers. Mayor’s Directive 18-2, “City in circle). and County of Honolulu Actions to Address Climate Change and Sea Level Rise,” requires the use of such information for a variety of City functions for planning, design, and long-term operations. This tool can also be Scan here to used by private landowners and developers to assess explore the what climate change-related hazards may impact their Climate Ready site, thereby informing design decisions. O‘ahu Web Explorer The Web Explorer incorporates SLR data from the State bit.ly/climatereadyoahumap of Hawai‘i Sea Level Rise Vulnerability and Adaptation Data Available on the Climate Report (2017), which utilized modeling of combined Ready O‘ahu Web Explorer : impacts from passive flooding due to SLR, annual high wave flooding, and coastal erosion to identify SLR- • SMA (Special Management Area) XA’s across the state for up to 3.2 feet of SLR (www. • TMK Parcels hawaiisealevelriseviewer.com). • Shoreline Change Rates (ft/yr); The Web Explorer also incorporates data from the historical & future National Oceanic and Atmospheric Administration • SLR-XA 3.2 ft - Potential Flooded (NOAA) SLR Viewer (https://coast.noaa.gov/slr/), Highways (State) which identifies areas impacted by 6+ feet of SLR. The • Erosion Zone - 3.2 feet SLR six foot level can be used for siting or designing critical • SLR-XA 3.2 ft - All Hazards (State); includes passive flooding, infrastructure or projects with a lifespan of 50 or more annual high wave flooding, & years. coastal erosion • Oahu Digital FIRM • SLR 6 ft (NOAA) • Heat Index - Afternoon • Tree Canopy - Land Cover (2010)

3 Climate Adaptation Design Principles for Urban Development

Climate Ready O‘ahu Web Explorer - Urban Honolulu with 6 feet SLR-XA

Climate Ready O‘ahu Web Explorer - Aiea, TMK view with 3.2 feet SLR-XA

Climate Adaptation Design Principles for Urban Development 4 B: Managing Stormwater Collect, Slow, and Infiltrate Stormwater with Green Infrastructure and LID

Climate change is expected to increase the frequency and intensity of storms in Hawai’i, making stormwater management a key concern for resilient site design. In addition to complying with existing rules, the following are recommended strategies for managing stormwater:

• Minimize impervious surfaces in site design; • Adopt strategies to infiltrate, evaporate, and reuse rainwater; • Utilize LID and green infrastructure strategies that increase detention and manage the rate of stormwater flow; and • Install stormwater infiltration, detention, and storage.

Specific examples of LID and green infrastructure technologies include bioswales, rain gardens, rainwater harvesting for reuse, green roofs, blue roofs, living walls, and detention basins or tanks. Trees and pavement suspension technologies or structural soils can also manage rainwater in dense urban environments. The City Storm Water BMP Guide for New

and Redevelopment (2019) provides details Source: City and County of Honolulu. “Post-Construction Water Quality Rules” on post-construction measures that can be integrated into building design. An appendix to the BMP Guide is currently under development that will provide more detailed specifications and guidelines for LID features, including infiltration basins Scan here for and trenches, vegetated bioretention basins, info on Post- permeable pavement and pavers, vegetated Construction BMPs swales, biofilters, and buffer strips. www.honolulu.gov/rep/site/ dfm/Post_Construction_ WQR_July_2019_booklet.pdf

5 Climate Adaptation Design Principles for Urban Development Green Infrastructure/LID Examples

Green Roofs Blue Roofs

PHOTO TO BE UPDATED

Capture and filter stormwater Temporarily store rainwater in detention systems Source: Hans van Heeswijk Architecten. “Rooftop Garden”. Amsterdam, Netherlands. Source: Flickr.com. “Green Infrastructure Pilot Projects in NY”. New York.

Living/Green Walls Rain Gardens

Help to filter stormwater before it enters the storm drain Store and collect rainwater as well as filter overflow Source: Hawaiilife.com. “Living Walls are Becoming Popular in Honolulu”. Ala Moana Center. Source: Behance.net. “Rain Garden Display Panel”. Kailua.

Detention tanks Permeable Pavements Source: City and County of Honolulu. “Post-Construction Water Quality Rules”

Store rainwater that can be reused for irrigation and indoor Capture water in place while filtering it and potentially non-potable uses following plumbing codes replenishing aquifers Source: Artspace.org. “Olas Ka‘ilima Artspace Lofts”. Honolulu. Source: Google Maps. “Street View Kapiolani Park”. Honolulu.

Climate Adaptation Design Principles for Urban Development 6 C: Design for Flooding and Sea Level Rise Elevating with Freeboard and DFE Land use and zoning regulations for where and how development occurs are some of the primary tools to mitigate against the impacts of direct and permanent SLR and groundwater inundation (e.g., the extent to which development may be allowed in hazardous areas). Additionally, to mitigate and protect against future event-based flooding, municipalities are exploringDesign Flood Elevations (DFE) that require building for greater inundation as a result of SLR and/or more extreme rainfall events. This

concept uses BFE from Federal Emergency Source: NYC Mayor’s Office of Recovery and Resiliency. “Climate Resiliency Design Guidelines”. Management Agency’s Flood Insurance Rate Maps (FEMA FIRM), plus freeboard and other risk factors to account for greater inundation. Raised Building Transitions to In addition to compliance with existing Pedestrian Zones regulations, such as ROH Chapter 21A Flood Hazards Areas and ROH Chapter 16 Building Code, anything below DFE/BFE should be floodproofed and designed to withstand loads from projected flooding. Sensitive uses and equipment, such as power systems and residential units, should be elevated above the ground floor or DFE/BFE. Utility connections below the DFE/BFE, and underground utilities within areas subject to groundwater inundation, should be waterproofed as well as account for a transition to future elevated Source: DP Architects. Wisma Atria. Singapore. streets. For larger flooding events, sites can also be designed to include features that provide both function and flood retention, such as floodable parking structures and plazas, or wetland areas that can accommodate greater flows. Likewise, on-site rainwater harvesting can be used for the dual benefit of flood mitigation and water conservation.

7 Climate Adaptation Design Principles for Urban Development Dry Floodproofing, Wet Floodproofing, and Elevated Floodproofing

The difference between dry floodproofing and wet floodproofing Dry floodproofed townhome Source: City of New York. “Coastal Climate Resilience: Designing for Flood Risk”. Source: Smithsonianmag.com. “This House is Built to Withstand the Force of a Tsunami”. Comano Island, WA.

Ground floor windows designed to withstand high water pressures Wetland character stormwater retention park with steel bulkheads Source: Greenworkspc.com. “Tanner Springs Park”. Portland, OR. Source: Flooddefences.org. “Germany, Hamburg”. Hafen City, Hamburg.

Climate Adaptation Design Principles for Urban Development 8 D: Mitigating Extreme Heat

As the atmosphere warms, Hawai‘i can Design Recommendations to Mitigate expect more record high temperatures Extreme Heat and heat waves, which bring associated threats to human and environmental Urban Tree Canopy health. Design recommendations to mitigate extreme heat include: • Providing shade through trees, awnings, or canopies; • Using high solar reflectance building materials and colors for windows, pavements, and coatings, within acceptable local ordinances. (See ROH Chapter 21 Land Use Ordinance for special districts design details and requirements); • Promoting landscaping on rooftops and around buildings for cooling; and

• Designing common outdoor areas with Source: Honolulu Civil Beat. “Bringing Order to Design Chaos at Manoa”. Honolulu. shade, seating, shelters at bus stops, and other amenities. Trees are long-term green infrastructure features with a recognized and Landscaping and Vegetation substantial return on investment. An urban tree canopy offers multifaceted benefits, including heat mitigation, carbon sequestration, stormwater management, improved air quality, energy savings, and business enrichment.

Scan here for the O‘ahu Community Source: City and County of Honolulu. “Design Guidelines: Transit-Oriented Development”. Honolulu. Heat Map

bit.ly/oahuheatmap

9 Climate Adaptation Design Principles for Urban Development Awnings

PHOTO TO BE UPDATED

Source: City and County of Honolulu. “Design Guidelines: Transit-Oriented Development”. Honolulu.

Living/Green Walls

Source: City and County of Honolulu. “Design Guidelines: Transit-Oriented Development”. Honolulu.

Solar Reflective Roofing Building Materials

Source: Coolroofstore.net. “The Cool Roof Store Hawai‘i”. Honolulu.

Climate Adaptation Design Principles for Urban Development 10 Three Common Typologies for Resilient Buildings & Site Design This guidance provides resilient design recommendations for three building typologies that are representative of existing and new development in urban Honolulu: 1: Tower & Podium | 2: Mid-Rise | 3: Low-Rise Walk-Up The following section includes graphics and descriptions showing common features of each building typology and applicable best practices for resilient design, with an emphasis on building-scale urban design solutions and principles for streetscape transition zones. Many of the design solutions described for one building type can be used for other building types and uses.

Resilient Streetscape Transition Zone The Resilient Streetscape Transition Zone is the area between the street curb and building façade, providing for an accessible slope up to the building’s required BFE or DFE (until adjacent streets and other properties are raised to same level). This zone should mitigate the impact of the elevation change on the public realm by including amenities such as flood- resistant plantings, sidewalks, seating, trees, awnings, and other placemaking elements or Private Land Public Right-of-Way design considerations.

Example of Desired Resilient Streetscape Transition Zone Source: City and County of Honolulu. “Transit-Oriented Development and Green This zone typically transcends from the project Infrastructure”. site into the public right-of-way (ROW), and also interfaces with adjoining properties. Consequently, these principles will require public and private landowner collaboration, including partnerships and agreements over Scan Here for the construction and maintenance responsibilities, ADA Accessibility to plan a coherent street block and pedestrian Guidelines streetscape that minimizes the impacts of hills/

www.access-board.gov/ valleys and off-site drainage. guidelines-and-standards/ buildings-and-sites/ about-the-ada-standards/ As all improvements must comply with background/adaag existing regulations and standards, including the Americans with Disabilities Act (ADA) Accessibility Guidelines, certain modifications will likely need to be considered.

11 Climate Adaptation Design Principles for Urban Development REPRESENTATIVE BUILDING TYPOLOGIES

2. MID-RISE

1. TOWER & PODIUM 3. LOW-RISE WALK-UP

Sources: 1. TOD. “Keahou Place”. Honolulu, HI. 2. “Redfin Estimate for 400 Keawe”. Honolulu, HI. 3. TOD. “Low-Rise Façade”. Honolulu, HI.

Climate Adaptation Design Principles for Urban Development 12 1: TOWER & PODIUM

Description 1 The Tower & Podium building typology is a commercial or residential tower constructed over a multi-level, mixed- use podium structure. On large lots, tower height ranges from eight to 40 or more stories with residential and/or commercial uses. A three- to seven-story podium base typically contains retail, residential, recreational, building lobby space, or some combination of these uses. The tower’s scale and density are mitigated by façade stepbacks and building articulation. The podium is designed to be of pedestrian scale with a high degree of ground floor transparency. Exposed portions of any 2 structured parking provided in the podium base are wrapped by residential floors or retail development, or screened from view by landscaping or decorative mesh. The Resilient Streetscape Transition Zone includes flood-resistant landscaping, pedestrian amenities, shade structures, and paths for use by the building tenants and the general public. The building is typically located along a high-volume “complete street” that provides equitable access to the development and balances transport modes, with 3 emphasis on active mobility, including walking and bicycling. Key Climate Resilient Design Guidelines 1. Provide amenity-rich Resilient Streetscape Transition Zone, which includes saltwater tolerant plantings, flood damage-resistant landscape materials, and green infrastructure. 2. Provide shade structures in the Resilient Streetscape Transition Zone and wide tree canopy in the planter strip zone between the road and sidewalk. 4 3. Provide sustainable roof systems, such as blue-green roofs, energy producing roofs, and reflective roofs. These systems can mitigate heat island effect; capture, treat, provide on-site reuse, and release stormwater; generate solar energy; and provide space for urban gardening and tenant amenities. 4. Locate critical systems above the BFE or DFE (on roof and/or on intermediate floors), including heating, ventilation, and air conditioning (HVAC) and power Sources: 1. Studio DWG. “Pedestrian Pocket Patio”. Austin, TX. generators. 2. Asla.org. Urban Grove at Central Harf Plaza, Boston, Charles Mayer Photography. 3. Unknown. “Rooftop Garden”. Singapore. 4. www.thomasnet.com/insights/how-cities-are-driving- growth-in-the-green-roofing-market

13 Climate Adaptation Design Principles for Urban Development Roof top solar panels

Elevated mechanical and electrical equipment

High performance building envelope to reduce HVAC system demands Optimized shading on façades to 4 reduce solar heat gain Blue-green roof to mitigate heat island effect, capture, treat, and release stormwater and generate solar energy

Active ground floor use Increased areas of vegetation, shading, and high reflectance materials to reduce Stormwater cisterns at podium level heat island contribution to collect and reuse water on site

Stair and ADA ramp up to Multistory parking sidewalk at intersection podium 3

2 Intermediate mechanical, electrical and plumbing (MEP)equipment space

Bicycle lane

Transit lane Climate Resilient TOD Dry floodproof space below the DFE Streetscape design and transition zone incorporates stormwater infiltration strategies. Resilient Streetscape Transition Zone Elevated residential or office lobby

Complete Street

Resilient Streetscape Transition Zone Detail

D Design Flood Elevation

A B C Standard Design Elevation DFE varies E F

A Bike Lane E Active ground floor use

B Transitional planters F Raised ground floor

C Tree lawn G Supporting Infrastructure

G D Street furniture

All Resilient Transition Zones must be ADA compliant

Climate Adaptation Design Principles for Urban Development 14 2: MID-RISE

Description 1 The Mid-Rise building typology is a four- to seven-story building that typically contains residential units above active ground floor uses, such as a lobby or retail space, that is visually and physically accessible from the public ROW. Residential units may be provided on the ground floor of the building. If off-street parking is provided, it is obscured from the public ROW, such as a parking structure wrapped by residential floors or sited at the back of the lot. Typical layouts for Mid-Rise buildings include rectangular, U-shaped, L-shaped, and perimeter building forms with 2 3 internal courtyards and green roofs. Flood resilient features, such as green infrastructure, saltwater tolerant plantings, and flood damage-resistant landscape materials, are provided within the Resilient Streetscape Transition Zone. These features allow for a welcoming forecourt to the building’s ground floor. The building is normally located along a “complete street” that provides equitable access to the development and balances transport modes, with emphasis on active mobility, including walking and bicycling. 4 Key Climate Resilient Design Guidelines 1. Provide an amenity-rich Resilient Streetscape Transition Zone, which should include saltwater tolerant plantings, flood damage-resistant landscape materials, and green infrastructure. 2. Provide landscaped surfaces, wide canopy trees, and shade structures, such as over seating areas, to mitigate the heat island effect. 3. Provide sustainable roof systems, such as blue-green roofs, energy producing roofs, and reflective roofs. These systems can mitigate heat island effect; capture, treat, provide on-site reuse, and release stormwater; generate solar energy; and provide space for urban gardening and tenant amenities. 4. Provide systems for on-site water reuse, which can aid in 5 water conservation and flood mitigation through rainwater capture. Cisterns at the podium level can irrigate on site and in the Resilient Streetscape Transition Zone. 5. Locate critical systems above BFE or DFE (on the roof or intermediate floors), including HVAC and power generators.

Sources: 1. Townshend Landscape Architects. “Sidewalk”. London, UK. 2. TOD. “South Shore Market”. Honolulu, HI. 3. Hans van Heeswijk Architecten. “Rooftop Garden”. Amsterdam, Netherlands. 4. Andrew Neuman. “Ola Ka ‘Ilima Artspace Lofts”. Honolulu, HI. 5. Finegardening.com. “Outtakes from a Rooftop Garden”.

15 Climate Adaptation Design Principles for Urban Development Blue-green roof to mitigate heat island effect, capture, treat, and release storm water and Elevated mechanical and electrical generate solar energy equipment screened from view

5 Stormwater cistern to collect and reuse water on site

Streetscape design and transition zone incorporates stormwater infiltration strategies 4 Multistory parking Active ground floor structure uses

Bicycle lane

2 1 Flood-proof parking structure below the DFE

Climate Resilient TOD Rooftop garden with Permeable shade structure pavement Elevate residential or office and space for urban for on-street lobby gardening parking

Active ground Resilient Streetscape floor uses Transition Zone

Complete Street Resilient Streetscape Transition Zone Detail

B G Design Flood Elevation

C Standard Design Elevation DFE varies

A D A Permeable pavement F Supporting infrastructure H B Bike lane G Planters with seating Transitional landscape C H Active ground floor use E D Parking entrance

F E Barrier-free ADA ramp up to sidewalk from intersection All Resilient Transition Zones must be ADA compliant

Climate Adaptation Design Principles for Urban Development 16 3: LOW-RISE WALK-UP

Description 1 The Low-Rise Walk-Up building typology is an attached, two- to four-story multi-family residential building. The first floor is built several feet above the BFE or DFE, allowing for an additional layer of privacy and the option of parking underneath. The building has a relatively shallow setback from the street edge, which provides space for pedestrian access and flood-resilient features in the Resilient Streetscape Transition Zone, such as green infrastructure, saltwater tolerant plantings, and flood damage-resistant landscape materials. Blue/green roofs can provide additional green space for urban gardening, 2 aesthetics, heat management, and rain catchment for irrigation. If off-street parking is provided, it is either sited at the rear of the development or as an integrated “tuck-under” parking garage, and not prominently viewed from the public ROW. Access to the parking may be provided by a mid-block driveway or alley behind the development. The building is typically located along a local street with relatively low traffic volumes. These streets could have a travel lane in each direction, pedestrian and bicycle infrastructure, and on-street parking. Bi-directional cycle track Key Climate Resilient Design Guidelines 1. Provide a Resilient Streetscape Transition Zone. Include saltwater tolerant plantings, flood damage- resistant landscape materials, and green infrastructure. 2. Provide building façade enhancements with street trees and other green elements to soften or screen parking from public view. 3. Provide wet floodproofed basement or storage area below BFE or DFE. 4. Site critical mechanical and electrical systems on the roof, including HVAC and power generators. 3 4 Visually screen mechanical equipment from view with landscaping and/or decorative fencing.

Sources: 1. Taylor Cullity Lethlean with Wright + Associates. “Rain Garden”. Auckland, New Zealand. 2. TOD. “Low-Rise Façade”. Honolulu, HI. 3. Indianafoundation.com. “Crawl Space Dehumidifier”. 4. Dilkhush Landscaping. “Rooftop Garden”. New Dehli, India.

17 Climate Adaptation Design Principles for Urban Development Exterior stairway to access residential units

Stormwater cistern to collect and reuse water on site Rooftop garden with shade structure and space for urban gardening Streetscape design incorporates stormwater infiltration strategies Raise residential units above the DFE on fill or above a wet-flood proofed basement or crawl space and provide access via stairway or ADA ramp 4

At-grade, off-street parking in attached structure

1 3 2

Bi-directional cycle track Wet-flood basement/ Climate Resilient TOD storage area Ground floor uses to include laundry, building office, etc. Resilient Street- scape Transition Zone Louvers to reduce solar heat gain

Property line Complete Street

Resilient Streetscape Transition Zone Detail

C B Design Flood Elevation

E Standard Design Elevation DFE varies A

D A Cycle track F Supporting infrastructure G B Permeable pavement G Wetflood proofed storage C Transitional landscape space/basement

D Parking entrance

F E Building lobby or office use to pro- mote active frontage All Resilient Transition Zones must be ADA compliant

Climate Adaptation Design Principles for Urban Development 18 Relevant Links & Resources CODES & ZONING Guidance on Revisions to the Revised Ordinance of Honolulu Chapter 23, Regarding Shoreline Setbacks. Hawai‘i State Building Code (2012 International (2019). Climate Change Commission. Available from: Building Code). (2018). Available from: https://resilientoahu.org/climate-change-commission https://ags.hawaii.gov/wp-content/uploads/2012/09/ Ola: O‘ahu Resilience Strategy (2019). City and County buildingcode-20170918.pdf of Honolulu, Resilient O‘ahu, 100 Resilient Cities. ROH Chapter 14: Public Works Infrastructure Available from: https://resilientoahu.org/resilience-strategy Requirements Including Fees and Services. (2019). Sea Level Rise & Climate Change White Paper. (2018). Available from: Sea Grant University of Hawai‘i. Available from: www.honolulu.gov/ocs/roh/193-site-ocs-cat/964-chapter-14- https://cc3cbeb5-ec5a-4085-a604-bf234e6332b7.filesusr.com/ public-works-infrastructure-requirements-including-fees-and- ugd/e3bef4_895ce353905246679264395f47f764ef.pdf services Sea Level Rise Guidance. (2018). Climate Change ROH Chapter 16: Building Code. (2020). Available from: Commission. Available from: https://static1.squarespace. www.honolulu.gov/rep/site/ocs/roh/ROH_Chapter_16a1_vb__. com/static/5e3885654a153a6ef84e6c9c/t/5ef121c353b pdf df278e3e4d253/1592861125312/FINAL+ADOPTED+w_ ROH Chapter 17: Electrical Code. (2019). Available rev_+Sea+Level+Rise+Guidance+2018.pdf from: www.honolulu.gov/rep/site/ocs/roh/ROH_Chapter_17.pdf CLIMATE HAZARDS ROH Chapter 19: Plumbing Code. (2019). Available from: www.honolulu.gov/rep/site/ocs/roh/ROHChapter19.pdf Assessment of Groundwater Inundation as a ROH Chapter 21: Land Use Ordinance. (2018). Available Consequence of Sea Level Rise. (2012). Rotzoll, K., from: www.honolulu.gov/ocs/roh/193-site-ocs-cat/975-roh- Fletcher, C. Available from: www.nature.com/articles/ nclimate1725 chapter-21 Assessing the Feasibility and Implications of Managed ROH Chapter 21A: Flood Hazard Zones. (2017). Retreat Strategies for Vulnerable Coastal Areas in Available from: www.honolulu.gov/rep/site/ocs/roh/ROH_ Chapter_21A_.pdf Hawai‘i. (2019). Office of Planning, Coastal Zone ROH Chapter 23: Shoreline Setbacks. (N.D.). Available Management Program, State of Hawai‘i. Available from: www.honolulu.gov/rep/site/ocs/roh/ROH_Chapter_23__. from: https://files.hawaii.gov/dbedt/op/czm/ormp/assessing_ the_feasibility_and_implications_of_managed_retreat_strategies_ pdf.pdf for_vulnerable_coastal_areas_in_hawaii.pdf ROH Chapter 25: Special Management Area. (N.D.). Hawai‘i Sea Level Rise Viewer. (2017). Pacific Islands Available from: www.honolulu.gov/rep/site/ocs/roh/ROH_

Chapter_25_article_1_12.pdf Ocean Observing System. Available from: ROH Chapter 32: Building Energy Conservation Code. www.pacioos.hawaii.edu/shoreline/slr-hawaii/ Hawai‘i Sea Level Rise Vulnerability and Adaptation (2017). Available from: www.honolulu.gov/rep/site/ocs/ roh/ROHChapter32.pdf Report. (2017). Tetra Tech; DLNR; Office of Conservation and Coastal Lands. Available from: https://climateadaptation.hawaii.gov/wp-content/

CLIMATE POLICY uploads/2017/12/SLR-Report_Dec2017.pdf City & County of Honolulu Actions to Address Climate Multi-Hazard Pre-Disaster Mitigation Plan for The Changes and Sea Level Rise. (2018). Mayor’s City & County of Honolulu. (2019). Department of Directive 18-02. Available from: www.honolulu.gov/rep/ Emergency Management. Available from: site/dpptod/climate_docs/MAYORS_DIRECTIVE_18-2.pdf www.honolulu.gov/dem/resources/disaster-info Climate Adaptation: Background Research, International Sea-Level Rise Flooding and Related Impacts: Primary Best Practices and Local Initiatives (2020). City and Urban Core, Honolulu, HI. (2019). Habel, S. Available County of Honolulu. Available from: from: www.soest.hawaii.edu/GG/academics/theses/Habel_ www.honolulu.gov/rep/site/dpptod/climate_docs/Climate_ Dissertation.pdf Adaptation_Background.pdf Sea Level Rise Viewer. (N.D). NOAA Available from: Climate Change Brief. (2018). Climate Change https://coast.noaa.gov/slr/ Commission. Available from: www.resilientoahu.org/s/ Climate-Change-Brief.pdf

19 Climate Adaptation Design Principles for Urban Development STREETSCAPE TRANSITION Urban Reforestation Master Plan. (2006). City and County of Honolulu. Available from: https://resilientoahu. Complete Streets Design Manual. (2016). City and org/trees/learn-more County of Honolulu. Available from: www4.honolulu. Urban Tree Plan (2019). City and County of Honolulu. gov/docushare/dsweb/Get/Document-187742/160908%20 Honolulu%20Complete%20Streets%20Design%20Manual_ Available from: www.honolulu.gov/rep/site/dpr/duf_docs/ Final.pdf Urban_Tree_Plan_Final_Draft.pdf Urban Tree Canopy Report. (2013). U.S. Department of Agriculture. Available from: https://smarttreespacific. STORMWATER MANAGEMENT org/wp-content/uploads/Tree-Canopy-Report-Honolulu-2016_ Green Infrastructure for Homeowners. (2012). City revised091117.pdf and County of Honolulu. Available from: https://www. honolulu.gov/rep/site/dfm/green_infrastructure_homeowners. TOD DESIGN GUIDANCE AND noENV.pdf Greening Iwilei and Kapalama. (2018). U.S. NEIGHBORHOOD PLANS Environmental Protection Agency. Available from: Ala Moana Neighborhood TOD Plan. (2016). City and www.honolulu.gov/rep/site/dpptod/iwilei_docs/Greening_Iwilei- County of Honolulu. Available from: www.honolulu.gov/ Kapalama_Final_Report_6-18.pdf tod/neighborhood-tod-plans/dpp-tod-alamoana Post-Construction Water Quality Requirements. (2019). Aiea-Pearl City Neighborhood TOD Plan. (2016). City City and County of Honolulu. Available from: and County of Honolulu. Available from: www.honolulu.gov/rep/site/dfm/Post_Construction_WQR_ www.honolulu.gov/tod/neighborhood-tod-plans/dpp-tod-aiea- July_2019_booklet.pdf pearlcity Rules Relating to Water Quality (Title 20, Chapter 3). Airport Area TOD Plan. (2017). City and County of (2017). City and County of Honolulu. Available from: Honolulu. Available from: www.honolulu.gov/tod/ http://www.honoluludpp.org/LinkClick.aspx?fileticket=2-F-Yiv5W neighborhood-tod-plans/dpp-tod-airport 8Y%3d&tabid=262&portalid=0&mid=3127 Downtown Neighborhood TOD Plan. (2020). City and Storm Water BMP Guide for New and Redevelopment. County of Honolulu. Available from: (2017). City and County of Honolulu. Available www.honolulu.gov/tod/neighborhood-tod-plans/dpp-tod- from: www.honolulu.gov/rep/site/dfmswq/SW_BMP_Guide_ downtown REVISED_July_2017.pdf East Kapolei Neighborhood TOD Plan. (2020). City and County of Honolulu. Available from: www.honolulu.gov/ TREES AND LANDSCAPING tod/neighborhood-tod-plans/dpp-tod-east-kapolei Actions to Address Increasing Temperatures and the Halawa Area TOD Plan. (2017). City and County of Urban Tree Canopy. (2020). Mayor’s Directive Honolulu. Available from: www.honolulu.gov/tod/ 20-14. Available from: https://static1.squarespace.com/ neighborhood-tod-plans/dpp-tod-halawa static/5e3885654a153a6ef84e6c9c/t/5f10cdd16f3e68586cad5d Kalihi Neighborhood TOD Plan. (2017). City and County 9c/1594936838963/Mayors+Directive+20-14.pdf of Honolulu. Available from: www.honolulu.gov/tod/ Community Forestry. (N.D.) City and County of neighborhood-tod-plans/dpp-tod-kalihi Honolulu. Available from: www.honolulu.gov/cms-dpr- TOD Special District Design Guidelines. (2019). City menu/site-dpr-sitearticles/35975-community-forestry and County of Honolulu. Available from: http://www. O‘ahu Community Map. (2019). Office of Climate honoluludpp.org/Portals/0/pdfs/zoning/TOD%20Guidelines%20 Change, Sustainability, & Resiliency. Available 2-5-19.pdf from: http://cchnl.maps.arcgis.com/apps/View/index. Waipahu Neighborhood TOD Plan. (2014). City and html?appid=ff1b73d836074cf6b2aca420fffbd930 County of Honolulu. Available from: www.honolulu.gov/ Rules and Regulations Relative to Planting and tod/neighborhood-tod-plans/dpp-tod-waipahu Maintenance of Street Trees. (1971). Department of Parks and Recreation. City and County of Honolulu. Available from: www.honolulu.gov/rep/site/dpr/rules/Rules_ Trees_Street.pdf Trees for Hawai‘i’s Future Website. (N.D). Available from: www.treesforhonolulu.org/

Climate Adaptation Design Principles for Urban Development 20 Definitions

• Base Flood Elevation, or BFE, is the computed elevation to which the flood is anticipated to rise during the base flood. The base flood is also referred to as the one-percent annual chance flood or 100-year flood.

• Design Flood Elevation, or DFE, refers to a base flood elevation that incorporates future SLR and flooding projections.

• Federal Emergency Management Agency Flood Insurance Rate Map, or FEMA FIRM, is described as “the official map of a community on which FEMA has delineated both the special hazard areas and the risk premium zones applicable to the community” (FEMA Flood Map Service Center, 2017). The FIRM is the basis for determining subsidies available to communities with floodplain management through the National Flood Insurance Program (NFIP).

• Freeboard is the elevation of a building’s lowest floor above predicted flood elevations by a small additional height. Freeboard is not required by the NFIP standards, but local governments are encouraged to adopt at least a one-foot freeboard to account for the one-foot rise built into the concept of designating a floodway and the encroachment requirements where floodways have not been designated.

• Right-of-Way, or ROW, is a public path, road, or area of land that people are legally allowed to travel along.

• Sea Level Rise Exposure Area, or SLR-XA, is identified in the State of Hawai‘i’s Sea Level Rise Vulnerability and Adaptation Report. SLR-XA was developed based on modeling that combines anticipated impacts from passive flooding due to SLR, annual high wave flooding, and coastal erosion.

Stay Informed If you have questions or comments on this document, please contact [email protected].

Acknowledgments: This project was undertaken by a consulting team from SSFM International and Arup for the City Department of Planning and Permitting Transit-Oriented Development Division and the City Office of Climate Change, Sustainability, and Resiliency. The scope of work included review of existing plans, guidelines, and projects; interviews with City agencies and design professionals; preparation of a background research document on international best practices and local initiatives; and development of this document.